Psychology Undergraduate Research Conference
Book of Abstracts for PURC 2016
Table of Contents
Motor Influences on the Semantics of Word Judgment
The Effect of Sex on Room Categorization Capabilities by Spatial Layout
Jessica L. Nardolillo
The Effects of Stress on Association-Memory
Food and Body Preferences
Examining the Relationships between Attention Allocation, Delay Discounting, Correlates of Working Memory, Social Anxiety and Social Phobia in an Undergraduate Population
Advisor: Gene Heyman
Attention is an essential element of executive functioning, especially in today’s ever-growing, stimulus-rich environment. Individuals must be able to pay attention to details and patterns, as well as purposefully and efficiently shift their allocation of attention from one stimulus to the next. Another aspect of executive functioning that goes hand in hand with attention is working memory. In the psychological literature, connections have been made between the efficiency with which individuals allocate their attention to relevant stimuli and working memory capacity. Attention is also thought to play an underlying role in some psychological disorders and impulsive behaviors. Through the use of a newly developed attention allocation procedure, delay discounting, vocabulary testing, and questionnaires pertaining to social anxiety and social phobia, this study seeks to investigate the possible relationships between these cognitive and psychological domains within a population of undergraduate students. Findings suggest a negative correlation between attention allocation efficiency as judged by accuracy values and social anxiety and phobia scores. Additional correlations are explored utilizing data pertaining to participants’ gender and concentration of study. Future applications of this research may influence attentional training, further examine additional factors that could affect delay discounting rates such as SES, and inform future studies of attention inefficiency in social anxiety and phobia disorders.
Keywords: attention allocation; working memory; delay discounting; chance payoff; impulsivity; social anxiety; social phobia
Linear, Numeric Board Games and Mental Representations of Number
Advisors: Fanny Gimbert, Karina Hamamouche, and Sara Cordes
Research shows that young children engage in play that promotes numerical and mathematical understanding. Children’s toys and games often reinforce spatial representations of number. Specifically, linear, numeric board games have been shown to improve children’s symbolic understanding of number (assessed by performance on a number line task); however, it is unclear if these board games impact children’s non-symbolic representations of number. Past research suggests that young children rely on a non-symbolic, approximate number sense, and that its acuity correlates to mathematical performance. This study seeks to replicate previous findings showing the positive impact of linear, numeric board games on children’s symbolic understanding of number. We also aim to extend these findings by exploring whether numerical board games have a similar effect on children’s non-symbolic understanding of number. Children were randomly assigned to the Number or Color (control) condition. Children participated in a pre-test, training, post-test design. During pre- and post-test, children completed tasks measuring symbolic (Number Line Performance) and non-symbolic (Numerical Discrimination Performance) number representations. Then, children and their caretaker were shown how to play our board game and asked to take it home and play it between six and eight times before returning to lab two weeks later for post-testing. Our preliminary data demonstrate that children in the number condition are showing slight improvement for Number Line performance at Time 2; however, this effect is not significant. There is a marginally significant (p=.06) negative correlation between performance on the Number Line task and performance on the Approximate Number task, suggesting that children’s representations of symbolic and non-symbolic number are related. After data collection is completed, we expect a significant effect of Time and Condition on both Number Line and Approximate Number Performance.
Concrete versus Abstract Thinking: A Relevant Factor in the Parent-Child Transmission of Math Beliefs
Advisors: Sara Cordes and Michelle Hurst
The current study looked at concrete or abstract mathematical thinking as a relevant factor impacting various aspects of mathematics in both children and their parents by using measures of math ability, attitudes about the difficulty of math, math anxiety, and concrete or abstract mathematical thinking. We specifically examined these ways of thinking about math as possible factors in the transmission of mathematics beliefs from parents to their children during parent-child teaching interactions. In order to investigate these questions, we asked parents to teach their children (grades 1-3) about specific fractions, a concept that their child may just be beginning to learn about but is still relatively novel. The teaching sessions were coded to look at how parents taught the fractions (e.g., the number and type of representations used). We found that a parent’s belief about math being abstract was related to their math difficulty attitudes and math anxiety. In addition, children’s ability to think abstractly was related to their fraction understanding. These two results together suggest that attitudes about abstract thinking and/or abstract thinking itself may be a relevant dimension when investigating math attitudes and ability. A look at teaching behavior revealed that the teaching had relatively low variability; most parents used discrete area representations without explaining the meaning of a fraction. Thus, we were unable to fully look at individual differences in teaching choices; however, there are some hints that parents may have taught more concretely to children who were less knowledgeable about fractions and more abstractly to children who were more knowledgeable about fractions. The study is currently ongoing, but we discuss the implications and future directions of this work.
Assessing the Timing of Judicial Instructions: Evidence from Psychological Research
Advisors: Jessica Karanian, Sharon Beckman, and Scott Slotnick
Among United States jurisdictions, there is no legal consensus on the most effective time within a trial to provide judicial instructions. In fact, many courts are either silent on the timing of juror instructions or leave the decision to the discretion of the judge. Over the years, legal scholars have argued both for and against the provision of juror instructions prior to evidence presentation and/or closing arguments. However, there is currently no uniform practice among U.S. jurisdictions. In the present study, we turned to the psychological literature to determine if there is a scientific consensus on whether jurors should be instructed prior to (pre-instructions) or after (post-instructions) evidence presentation and/or closing arguments. A thorough search of research databases, such as Pubmed, PsychINFO, ProQuest Social Science Journals, and PsycARTICLES, was conducted. We utilized search terms such as judicial instruction timing, juror instructions, timing of trial instructions, jury instructions, instructions and juror competence, preinstructions, postinstructions, and preliminary instructions. Of the 13 empirical research papers identified for inclusion, 11 studies provided evidence in favor of providing judicial instructions prior to presentation of evidence and/or closing arguments. The benefits of pre-instruction included decreased pro-plaintiff biases, increased organization of evidence, better allocation of attention to relevant trial information, and more accurate decision-making in mock jurors. Therefore, the psychological evidence suggests that juror performance is enhanced when instructions precede evidence and/or closing arguments. However, future studies will be needed to fully understand the benefits and potential downsides of presenting juror instructions prior to evidence presentation and/or closing arguments.
The Effect of Sex, Age, and Maternal Separation on Oxytocin Receptor and Vasopressin V1a Receptor Binding Density in Early Postnatal Development
Advisors: Alexa Veenema and Kelly Dumais
Oxytocin (OT) and vasopressin (VP) are evolutionarily conserved neuropeptides that are key regulators of social behavior. Significant sex differences in OT receptor (OTR) and VP V1a receptor (V1aR) binding density are found in the adult rat brain, but the developmental stage when these sex differences emerge is unknown. To address this, we analyzed OTR and V1aR binding density in male and female rats at postnatal days (P) 5, 12, and 35. Overall, sex differences in OTR and V1aR binding density were limited during early postnatal development, and were only found in the posterior bed nucleus of the stria terminalis (BNST) and globus pallidus (GP; both showing higher OTR binding density in males) and the lateral dorsal BNST and reticular thalamus (both showing higher V1aR binding density in males). In contrast, all of the analyzed brain regions showed robust age differences, and in many brain regions, OTR or V1aR binding density was higher at P12 than P5 or P35. To better understand the functional implication of peak receptor binding at P12, rats were subjected to daily maternal separation, which is known to modulate OTR in the adult brain. Maternal separation reduced OTR binding density in the GP and the medial amygdala, but did not affect olfactory discrimination, in P12 pups. These results indicate that the emergence of sex differences in OTR and V1aR binding happens later in life, and that early postnatal development is dominated by robust age differences, many of which involve peak receptor binding at P12. Despite its prevalence, the functional significance of peak OTR and V1aR receptor binding remains unknown. A direct investigation of the brain regions that show peak receptor binding may provide information about the role of this widespread developmental pattern of OTR and V1aR.
Theory of Mind for Action Prediction and Explanation during Cooperative and Competitive Social Interactions
Advisors: Liane Young and Lily Tsoi
Being able to successfully explain and predict people’s behaviors requires the capacity to reason about people’s beliefs, desires, and intentions. We examine whether the extent to which people engage in mental state reasoning or theory of mind differs across action types (explanation vs. prediction) and social contexts (cooperation vs. competition). In a behavioral study, pairs of participants played a game variant of “Rock, Paper, Scissors;” each person had to either match or mismatch the shape of the other person. Trials were either all cooperative (e.g., both players have to match) or all competitive (i.e., one person has to match while the other has to mismatch). On a subset of trials, participants were prompted to either write about (1) their prediction of the other player’s future shape response and reasons for their prediction or (2) their explanation for the other player’s revealed shape response. Each written response was coded for the absence or presence of mental state information. While there was no interaction between social context and action type, there were main effects of social context and action type. Specifically, the proportion of trials containing mental state information was greater for the compete condition than the cooperate condition, and the proportion of trials containing mental state information was also greater when participants had to explain versus predict the other player’s shape response. Intriguingly, the proportion of prediction trials containing mental state information was negatively correlated with a measure of autistic traits. These results suggest that the extent to which people spontaneously refer to the mental states of their interaction partners may differ depending on whether they are trying to make explanations or predictions of their interaction partner’s behaviors and whether the interaction is cooperative or competitive.
Gender and Mood Appear to Have No Impact on Reading of Facial Expressions
Advisors: James Russell and Mahsa Ershadi
Socially constructed differences between genders in the vast majority of societies from ancient to modern times has inspired an abundance of research on gender. It has been shown that participants show higher rates of accuracy in recognizing facial expressions if they are part of an in-group to which the participant belongs (Elfenbein & Ambady 2002). The present study was designed to examine whether men and women serve as in-groups. Mood inductions were also examined, to see if they would also affect the genders differently or influence the readings of facial expressions. Other studies have investigated the effects of mood induction on cognition or facial expression identification and found it impairs functioning (Chepenik, Farah, & Cornew 2007). This study, however, found no differences in the way men and women read facial expressions and found no effect of mood inductions. There were no significant differences between the genders within each mood induction, and no significant differences in each gender across mood induction conditions. These results suggest that American society is progressing in such a way that gender is no longer a deciding factor or inhibitor in reading of facial expressions; they are a basis for future research on cognition and emotion between in-groups and out-groups.
Prior Extinction Training Produces Greater Suppression on a Fixed-Interval Punishment Schedule
Advisor: Jef Lamoureux
In human and nonhuman animal learning, information obtained about excitatory cues transfers seamlessly from context to context with little to no change in the initial perception of what the cue means, resulting in the same response to that cue in both contexts (Bouton, 2004). During extinction of the cue, the new inhibitory CS-no US association competes with the initial CS-US association that developed during conditioning. This results in ambiguity of the cue in which the animal becomes uncertain of the relationship between the cue and the US. Previous studies suggest that extinction may enhance attention to contextual cues (e.g., Callejas-Aguilera & Rosas, 2010) and that time itself may serve as a context (Bouton, 1993). The current experiment was based on this idea of time as a context, employing a conditioned suppression task in which participants learned to reduce their click rate in a science-fiction computer game in response to sensors (CSs) predicting the onset of an enemy attack (US). Participants were trained on either a 15-second or 30-second fixed interval punishment schedule after an initial phase of excitatory CS conditioning and then a second phase in which they randomly received either extinction or no extinction training of the initial excitatory cue. Results failed to show temporally specific suppression to either punishment schedule, but the group that received the 30s punishment schedule and extinction training showed greater overall suppression of click rate. A nonsignificant trend of greater suppression following extinction training was also observed in the 15s groups. This enhanced learning in the extinction group provides some support for Rosas’ hypothesis that extinction may enhance attention to contextual cues.
No Evidence for Improved Scene Categorization When Objects Bias Scenes’ Properties
Advisor: Sean MacEvoy
An important task of the visual system is scene recognition, important for navigating and for coordinating behaviors when in a certain environment. It is well known that the kinds of objects in a room provide critical information about the identity of the room, but that scene can also be recognized on the basis of their spatial properties, like size. Previous work in our lab has shown that the kinds of objects within a scene can bias the perceived size of the scene towards the average size of type of scene. In the present study we tested the hypothesis that this biasing effect serves to aid scene categorization. Participants were asked to judge whether computer-generated rooms were kitchens or bathrooms, both when diagnostic objects were masked or unmasked. We predicted that object unmasking should improve scene categorization accuracy under conditions that allowed it to bias scenes’ spatial properties. Although we observed a clear improvement in categorization with object unmasking, this did not appear to depend on the amount of spatial property biasing. These results leave open the role, if any, in scene categorization of object-spatial property “crosstalk.”
Context-Specificity in a Predictive-Learning Task with Humans
Advisor: Jeffrey Lamoureux
The attentional theory of context processing (ATCP) suggests that all associative learning acquired while in an enhanced attentional state of context processing becomes specific to that context. The theory further suggests such intense context processing may be triggered when a training cue possesses predictive ambiguity. Prior studies have shown that predictive ambiguity induced by extinction of a previously-trained cue may enhance the context-specificity of a conditioned excitor trained around the time of extinction (e.g., Callejas-Aguilera & Rosas, 2010). The present study aims to replicate these previous findings using a methodology very similar to the prior published studies (Expt 1), while also examining the additional effects of trial sequencing (Expt 2), and the extinction paradigm employed (Expt 3). In Expt 1, participants received repeated trials in which they were explicitly told a person was in one of two restaurants, received one of a number of foods, and then either became ill or not. Participants were asked to rate the likelihood of illness on each trial. In all experiments, training was divided into two phases, the second of which involved a change in the associated outcome of one of the cues (i.e. extinction). Expt 2 was the same as Expt 1, except that training trials were presented in blocks of eight by context (ABBAAB), while in Expt1, trials were randomly intermixed throughout. Expt 3 compared AAB and ABA extinction paradigms. In all experiments, we found substantial context-specificity of conditioned predictive cues. However, in contrast to prior work, context-specificity was observed whether or not the participants were exposed to an extinction procedure, and regardless of trial sequencing. The results of Expt 3 suggest that context specificity is greater when acquisition and extinction occur in different contexts.
Learning How Gears Work: Does Drawing Strengthen Understanding?
Advisor: Ellen Winner
Many teaching practices aim to utilize the arts to expand the understanding of scientific concepts among schoolchildren (Frankel, 2014). Evidence suggests that self-generated drawings of certain scientific phenomena improve comprehension of the events themselves (Van Meter et al., 2006; Mason et al., 2013). The present study examines whether children’s basic understanding of gears can be expanded through drawing, in particular among second and fourth grade children. Forty-five second graders and 44 fourth graders were randomly assigned to one of two groups: drawing and no drawing. Each participant was given a gear system toy to study and manipulate. Those in the drawing group were asked to make a drawing that showed how the gears worked, while those in the no drawing group were just asked to observe the gears. A comprehension test consisting of four questions was then administered to determine whether children understood directionality, and the relation between the size of the gear and its speed. Contrary to prediction, the drawing group did not score higher in comprehension than the no drawing group. However, when drawings were scored for accuracy, children in the drawing group whose drawings showed that the first two gears moved in opposite directions scored higher on a question about the direction of the second gear when the first gear was turned. Unfortunately these results cannot distinguish between the possibilities that (1) accuracy in drawing facilitates understanding of the directionality of gears or (2) accuracy in drawing reflects previous understanding.
Motor Influences on the Semantics of Word Judgment
Advisor: Hiram Brownell
This paper on embodied cognition reports two experiments that examine conflicting motor-semantic compatibility effects using judgments of word valence. The classical compatibility effect characterizes movement towards the body as inherently positive and movement away from the body as negative. This has recently been demonstrated in a study in which participants respond while grasping a lever with a closed fist. The other, opposing compatibility effect predicts that an open-hand posture will reverse the classical compatibility effect of motion outwards as negative and motion inwards as positive. This is because open-handed outward movement typically precedes grasping an object in order to pull it inward. Participants in Experiment 1 (closed-hand grasp) responded more quickly with the classically compatible paring of positive response with a lever pull towards the body and a negative response with a lever push away from the body. Participants in Experiment 2 (open-handed reach) showed no evidence of the opposing compatibility effect and some evidence of the classical compatibility effect. In addition, groups of participants in Experiment 2 who also completed an intervening motor adaptation task showed no difference between compatible and incompatible response pairings, suggesting that compatibility effects are weakly if at all influenced by motor adaptation.
Oxytocin Facilitates Synaptic Plasticity in the Insular Cortex
Advisor: John Christianson
The neuropeptide oxytocin (OT) increases the likelihood of synaptic plasticity in areas such as the hippocampus and the nucleus accumbens. However, it is unknown whether or not OT modulates synaptic efficacy in the insular cortex, an area important for social learning. The purpose of this study was to characterize the effect of OT on long-term depression (LTD) induction in the insula. Acute brain slices containing the insular cortex were placed on a multiple electrode array, and each experiment began by scanning the array for excitatory postsynaptic potentials (fEPSPs) with a 3mV biphasic extracellular stimulation. After an appropriate fEPSP was chosen, very low frequency stimulation was applied for 30mins to establish a baseline and then OT (500nM) was added. The fEPSPs were observed for another 30mins, but there was no apparent effect of OT. In the following experiment, slices were treated in the same manner as above, except a low frequency stimulation (LFS) protocol (900 stimuli at 1Hz) was given to slices to induce LTD in either normal artificial cerebrospinal fluid (aCSF) or aCSF containing OT. LFS did not induce to LTD in aCSF, but two out of four slices showed LTD in the OT condition. These results imply that OT may facilitate learning processes in the insular cortex.
The Role of Opioids in the Regulation of Social Novelty-Seeking Behavior in Juvenile Rats
Advisors: Alexa Veenema and Caroline Smith
Seeking out and interacting with novel peers during the juvenile period promotes the development of adult social competence, as it facilitates independence from parents and the formation of new social ties. We have previously demonstrated the involvement of opioids in facilitating social novelty-seeking behavior in juvenile male rats. In the present study, we aimed to clarify the specific brain regions in which opioids might be acting to regulate social novelty-seeking. We focused on the nucleus accumbens (NAC) and the basolateral amygdala (BLA) as these regions modulate socially rewarding behaviors and express high levels of μ-opioid receptors (MOR) in juvenile rats. We predicted that inhibition of MORs in the NAC and BLA would decrease social novelty-seeking. Using a within-subjects design, we bilaterally injected CTAP, a MOR antagonist, into the NAC or BLA and assessed social novelty-seeking behavior in the social novelty preference test. In this test, subject rats are given the option to investigate their cage mate (familiar) or a novel conspecific. We found that blocking MORs in the NAC decreased time spent investigating the novel social stimulus and increased time spent investigating the cage mate, resulting in a decrease in social novelty preference. In contrast, blocking MORs in the BLA had no behavioral effect. We next determined whether the BLA in general modulates social novelty-seeking behavior by inhibiting BLA output with muscimol, a GABAA receptor antagonist, and measuring the effect on social novelty-seeking behavior. We found that inhibition of the BLA decreased social novelty-seeking behavior. Overall, these findings suggest that (i) MOR activation in the NAC, but not in the BLA, facilitate social novelty-seeking, and that (ii) BLA activation also facilitates this behavior. Overall, these findings are the first to suggest a neural circuit involving NAC-MOR and BLA activation in facilitating social novelty-seeking behavior.
Parent Interactive Reading as a Predictor of Cognitive Development
Advisors: Sara Cordes and Sophie Savelkouls
Prior research indicates that emergent literacy knowledge influences a child’s academic achievement across their life span. Children who fall behind in the first grade are 88% more likely to remain below grade level throughout elementary school, and are more likely to drop out of high school (Sloat, Letourneau, Joschko, Schryer, & Colpitts 2014). Therefore, there is a great need to examine how emergent literacy can be cultivated through everyday activities such as parent-child reading. This study investigated whether specific components of parent-child interactive reading not only correlated with language development, but also with other domains of cognitive development such as executive functioning and number understanding. Our results demonstrated that while our measures of parent-child interactive reading negatively correlated with language development, executive functioning, or numeracy development, we did find that both language development and executive functioning significantly predicted numerical understanding.
The Role of the Basolateral Amygdala in Adult Alcohol Drinking Established in Adolescence
Advisor: Michael McDannald
Adolescence is a critical period in brain development. During this time heavy alcohol drinking increases the risk for alcohol use disorders (AUD) in adulthood. AUDs are of increasing concern as they impose great health and financial burdens on to society. We propose that adolescent alcohol drinking alters the neural circuits for drinking and motivation in adulthood. Specifically, we hypothesize that the basolateral amygdala (BLA) is a critical brain structure in this circuit and that altered BLA function in adolescence increases the risk for AUDs in adulthood. To analyze the role of the BLA in adolescent drinking, we gave genetically heterogeneous, male Long Evans rats voluntary, chronic intermittent access to alcohol or a quinine-adulterated DuoCal® solution throughout adolescence. Rats then underwent BLA lesion or sham surgery. After a recovery period, we exposed rats to chronic alcohol access in adulthood to assess drinking levels. Heavy alcohol drinkers in adolescence showed a decrease in adulthood alcohol consumption after BLA surgery. Control solution BLA lesioned rats showed no significant preference for alcohol in adulthood. Our results demonstrate that the BLA is a critical structure targeted and altered by adolescent heavy drinking, implicating its role in increasing the risk for AUDs in adulthood.
Manipulating Minds to Motivate: Is Follow-Up Behavior Improved by Appealing to Goals vs. to Emotions?
Advisor: Andrea Heberlein
The purpose of the current research was to determine how framing a message in terms of Agency, which focuses on plans and goals, or Experience, which focuses on feelings and emotions, affects participants’ drive to engage in follow-up behavior. We tested this question in three different studies, two that modeled adherence behavior, and one that explored adherence in a hypothetical context. In Study 1, we recruited participants on the Boston College campus through two sets of flyers (Agency or Experience) that each had tabs with survey links for participants to tear off and follow to receive compensation. We found that more participants tore tabs off the Experience flyers, so the ratio of tabs torn off to tabs left on the flyers differed between the Agency and Experience conditions (p = .0004). Additionally, we found that more participants completed the Experience surveys, so the ratio of surveys completed to tabs torn off differed between the Agency and Experience conditions (p = .004). In Study 2, we recruited Boston College students online and required that they save a URL and use it 24 hours later to take a second survey in order to receive compensation. We found that the ratio of follow-up responses to initial responses did not differ between Agency and Experience conditions (p = .219). In Study 3, we recruited participants online through mTurk, gave them either agentic or experiential instructions in a hypothetical interaction with a physical therapist, and asked them to predict how they would respond. We found no significant effect between conditions. Our data therefore suggest that framing messages in a way that makes one think of oneself as an experiencer could increase motivation for follow-up behavior.
The Effect of Sex on Room Categorization Capabilities by Spatial Layout
Jessica L. Nardolillo
Advisor: Sean MacEvoy
This study examined the effect of sex on the ability to categorize images of rooms as bathrooms or kitchens based solely on their spatial layout. Navon (1977) originally found that global stimuli take precedence over local stimuli in the visual processing system, an effect now called the global precedence effect. Previous studies have found sex differences in the speed and ability of participants to recognize differences at global and local stimuli levels. Here we examined sex differences in the ability of participants to use a global feature—spatial layout—to categorize scenes. Thirty-nine participants (24 females) volunteered to categorize 300 room images as either kitchens or bathrooms, based solely on the size of the spaces. Based on previous anecdotal evidence showing that females may more consistently categorize rooms based on spatial layout (Linsley & MacEvoy, 2014), combined with studies showing that males have stronger global precedence, we hypothesize that there would be a sex difference effect on room categorization by spatial layout. This hypothesis was not supported by the data analysis, because almost all individuals showed consistent reliance upon the spatial layout to categorize the rooms. These results do not follow the trend seen by Linsley and MacEvoy (2014), and directly contradict previous studies showing sex differences in reaction times to global stimuli and studies showing a stronger male global preference. Rather, this study aligns with a study by Kimchi, Amishav, and Sulitzeanu-Kenan (2009), which showed no difference between males and females in global or local processing bias.
Investigating the Intersection of Sharing Behavior and Understanding of Division in Young Children
Advisors: Karina Hamamouche, Nadia Chernyak, and Sara Cordes
Division is often first presented to children in the form of a sharing problem. In the present study, we investigated whether a sharing activity primes 4- and 5-year-old children to succeed in a non-symbolic division task. Children were generally able to successfully transform a large quantity into half of its original value, suggesting that without prior teaching, children may have the ability to employ division strategies. The presence of a sharing task, however, did not improve children’s likelihood of performing above chance on a non-symbolic division task. Rather, more successful performances in both sharing tasks and non-symbolic division tasks were positively correlated with age.
Undergraduates’ Perception of Depression is Primarily Limited to Sadness
Advisor: James Russell Major
Depressive Disorder (MDD) is a prevalent and debilitating mental disorder with diagnostic symptoms that include depressed mood, diminished interest, fatigue, feelings of worthlessness or guilt, and thoughts about death. Previous research indicates there is negative stigmatization towards individuals diagnosed with MDD (Crisp et al., 2000; Scott et al., 2013). Two studies (N=40 and N=35) investigate undergraduates’ perception of depression by examining the emotions and facial expressions associated with depression. The first study found that undergraduates endorsed vignettes describing people with depression as depicting sadness, anxiety, fatigue, fear, and guilt at significant rates. However, undergraduates endorsed the vignettes with significantly more intense sadness than other emotions. The second study found that that undergraduates believe only sad facial expressions show how a person experiencing depression feels. Undergraduates’ understanding of depression is primarily limited to sadness. While depression certainly encompasses sadness, it involves other emotions as well. A limited understanding of depression can affect the way undergraduates recognize depression in themselves or their fellow students.
Age and Sex Differences in Forebrain Distribution of Vasopressin and Oxytocin Fibers in the Rat
Advisors: Brett DiBenedictis and Alexa Veenema
The neuropeptides vasopressin (AVP) and oxytocin (OT) have been implicated in the regulation of numerous social behaviors. AVP and OT signaling occurs within a circuit of interconnected brain regions known collectively as the ‘social behavior neural network’ (SBNN). Importantly, AVP and OT signaling within the SBNN differentially regulate various social behaviors depending on the age and/or sex of the animal. We hypothesized that variation in the display of these behaviors could be due to age and sex differences in AVP and OT fiber innervation within the SBNN. To test this, we conducted immunohistochemistry to visualize AVP- and OT-immunoreactive fibers in juvenile and adult male and female rats and subsequently quantified AVP and OT fiber density throughout the SBNN. We found robust age (higher in adult males and females) and sex (higher in juvenile and adult males) differences in AVP fiber density in the lateral septum, medial amygdala and preoptic area of the hypothalamus. In contrast, there were fewer age and sex differences in OT fiber density, and the direction of these differences was brain region-specific. In detail, OT fiber density was lower in adult males compared to juvenile males in the rostral lateral septum, higher in adult males compared to juvenile males in the anteroventral medial amygdala, and higher in adult females compared to adult males in the medial lateral septum. These findings suggest that AVP signaling in discrete SBNN nuclei may be particularly critical for behaviors expressed by adult males, while OT signaling may slightly favor adult female-typical behaviors, but in a brain region-specific manner. More work is needed to determine the causal involvement of age and sex differences in AVP and OT fiber density in the age- and sex-specific regulation of social behavior.
The Effects of Stress on Association-Memory
Advisor: Elizabeth Kensinger
Separately, stress and emotional stimuli are known to impact association-memory, but it is not clear how these two factors in combination affect recall. It has recently been reported that exposure to stress before retrieval impairs free recall for emotionally arousing stimuli. Emotionally arousing stimuli also have been found to impair association-memory retrieval. In the present study, 40 young adults learned a word list containing 20 positive, 20 negative, and 20 neutral Swahili-English word pairs and were tested on their memory for the word pairs after a one-week delay. Just prior to the delayed memory test, participants were exposed to the Cold Pressor Test (CPT), a reliable and effective method of inducing stress, or a control condition. Overall performance on the cued-recall task was not significantly different between stressed and control groups, where a greater proportion of positive word pairs were learned and recalled compared to negative and neutral word pairs. Upon further analysis, stress significantly impaired association-memory for negative word pairs compared to controls. The present study demonstrates that physiological stress effects association-memory retrieval differently for positive and negative emotionally arousing stimuli.
Key words: stress; emotion; episodic memory; association-memory; delayed cued recall
Age and Sex Comparisons in µ-Opioid Receptor Binding Densities in the Rat Brain
Advisors: Alexa Veenema and Caroline Smith
The µ-opioid receptor (MOR) system in the brain has been shown to mediate socially rewarding behaviors in juvenile rats, including social play behavior and social novelty seeking. Across species, juvenile animals are more inclined to engage in social interactions with peers and seem to find these interactions to be more rewarding than their adult counterparts. These age differences in behavior may be due to age-specific alterations in the MOR system. Therefore, we analyzed MOR binding density in brains of juvenile and adult male and female rats. Age differences were found in four out of the 23 analyzed brain regions—with denser MOR binding in juveniles than in adults in the CA1 and CA3 subregions of the hippocampus, the caudal subnucleus of the interpeduncular nucleus (IPC), and the paraventricular nucleus of the thalamus (PVT). Sex differences were found in two brain regions, namely the lateral subnucleus of the interpeduncular nucleus (IPL), which had denser MOR binding in juvenile males than in adult males, and the posteromedial cortical amygdaloid nucleus (PMCo), which had denser MOR binding in females than in males. These age and sex differences in MOR binding densities may have implications for age and sex differences in the regulation of socially rewarding behaviors. However, the observation of relatively few age and sex differences in MOR binding density throughout the brain, demonstrates that the MOR system is very stable. This may suggest that age and sex differences in the regulation of behaviors by the MOR system may not be mediated at the level of the receptor or that MORs play a role in the regulation of behaviors, regardless of age or sex. Overall, these findings provide an important framework for testing the role of MORs in the regulation of a variety of behaviors, across age and sex.
Involvement of the Ventral Tegmental Area in the Sex-Specific Regulation of Social Play Behavior by Vasopressin in Juvenile Rats
Advisors: Alexa Veenema and Remco Bredewold
Arginine vasopressin (AVP) regulates many social behaviors in adults, but little is known about its role in regulating social behaviors in juveniles, such as social play. Social play is rewarding and important for the development of social competencies. Furthermore, deficits in AVP and social play have been observed in individuals with neurodevelopmental disorders such as autism. To understand the neurobiological basis of social reward and the causes of social play deficits, it is necessary to explore the neural mechanisms by which AVP regulates social play. Our lab previously showed that AVP modulates social play in juvenile rats sex-specifically, regulated by the AVP 1A receptor (V1aR) in the lateral septum (LS). The aim of this thesis was to explore the involvement of the VTA, a downstream target of the LS that regulates reward, in the sex-specific regulation of social play. We hypothesized that the LS-VTA pathway would be activated during social play and that this activation would be altered in a sex-specific manner in response to LS-V1aR blockade. In contrast to our hypothesis, we found less neuronal activation of the VTA (as measured by c-Fos expression) in males that played compared to males that did not. Likewise, V1aR- antagonist treated females that played showed less c-Fos expression than V1aR-antagonist treated females that did not. Together, this suggests a sex-specific effect of social play and of LS-V1aR blockade on VTA activation. To further explore the involvement of the VTA, VTA output was inhibited by injecting GABA-A or GABA-B receptor agonists into the VTA and measuring social play. Play decreased in GABA-B receptor agonist-treated males compared to vehicle-treated males, suggesting the involvement of the VTA in social play in males. In conclusion, our preliminary findings are the first to suggest a role for the VTA in the sex-specific regulation of social play by LS-AVP system and that VTA activation is important for social play regulation in males, but not in females.
Inactivation of the Orbitofrontal Cortex Impairs Fear Discrimination
Advisor: John Christianson
Survival depends on flexible behavioral adaptation to shifting environmental risks and opportunities. Regarding environmental risks, delineating the mechanisms which permit acquisition, recall, and flexible use of aversive associations is crucial to unraveling the neural bases of trauma-related disorders: notably, people with PTSD are challenged when presented with aversive stimuli within safe environments. In the realm of desirable associations (such as stimulus-reward pairings), the orbital frontal cortex (OFC) is critical for integrating outcome expectancies with flexible behavioral respond. To test the role of the OFC in cognitive flexibility within an aversive learning domain, we developed a fear discrimination procedure in which adult male rats readily shift behavioral responses depending on the presentation of either a shock paired conditioned stimulus (CS+) or a safety cue (CS-). We then used either reversible pharmacologic inactivation with muscimol (GABAA receptor agonist) or chemogenetic silencing (KORD) to disrupt OFC functioning during a fear discrimination recall tests. Muscimol significantly diminished the ability of adult male Sprague Dawley rats to discriminate between safety and danger cues. However, chemogenetic silencing had no effect. These contradictory findings suggest there may be a part played by the OFC in aversive responding but that, if this is indeed the case, the function is primarily upheld by the region's network of interneurons rather than its pyramidal output.
Food and Body Preferences
Advisor: Jef Lamoureux
Past research has suggested that by establishing undue dislike of certain foods, evaluative conditioning may play a role in the development of eating disorders. By pairing various food items as conditioned stimuli (CSs) with different body types as unconditioned stimuli (USs), researchers have shown that foods paired with aversive stimuli may become more negatively rated (Lascelles, Field, & Davey, 2003). Importantly, later research suggested that this type of negative evaluative conditioning might not be affected by typical extinction procedures (Dwyer, Jarratt, & Dick, 2007). Our research set out to replicate these previous claims and to further understand this evaluative conditioning paradigm by investigating the effects of counterconditioning. Ninety-six participants were tested in either extinction or counterconditioning procedures; each subject received initial picture-picture conditioning in which pictures of foods were immediately followed by pictures of bodies. Some bodies were of the average BMI range and were rated positively by subjects, while other bodies were clinically obese, rated very negatively, and supported negative conditioning. Afterword, participants received either extinction training in which the food images were presented repeatedly in the absence of bodies, or counterconditioning training in which foods were followed by pictures of preferred (i.e. non-obese) bodies. The data replicated previous work, suggesting that in this food-body paradigm, extinction is not effective at reversing negative evaluative conditioning. Similarly, we found that counterconditioning of the predictive stimuli produced insignificant changes in ratings, albeit with a possible trend toward significance. In future experiments, we will use more positively-valenced USs—pictures of extremely attractive bodies—to examine if even the most appetitive stimuli are able to reverse negative conditioning in this paradigm. These results are important to understanding both evaluative conditioning in the context of associative learning theory, and potential therapeutic treatment options for those with disordered eating.
The Subjective Experience of Math: An Investigation into Student Attitudes toward Math Oriented Subjects
Advisors: Sara Cordes and Michelle Hurst
Given that few students successfully complete science, technology, engineering, or math (STEM) degrees and that many students have negative attitudes toward STEM fields, it is important to investigate how these attitudes may be related to individuals’ experiences in STEM majors. In the current study, 69 undergraduate students who were enrolled in math, computer science, or psychology courses completed a survey at two points during the fall semester (N=23), at one time point during the fall semester (N=40) or at one time point during the spring semester (N=26). Students were asked about attitudes towards math and/or computer science (depending on experience), such as the importance of effort, whether the domain is static (e.g., everything is already known) versus dynamic (e.g., you can figure out new things), perceived value (e.g., how useful it is for their future success), and belonging to the field. We found that attitudes about problem solving were related across math and computer science and beliefs about the importance of “debugging” (a programming specific concept) were related to beliefs about problem solving in computer science. The largest predictor of students’ positive experience in math was the degree to which they valued math. Lastly, preliminary data suggest there may be differences between students who intend to pursue more math courses and those who do not in their personal attitudes toward the subject (e.g., value). Future directions include running additional experiments to investigate the malleability of these attitudes about math and computer science in order to shed light on how these attitudes may be impacted by math experiences.
The Effects of Excitotoxic Lesions of the Dorsomedial Striatum on Pavlovian Appetitive Conditioning and Food Consumption
Advisors: Gorica Petrovich and Sindy Cole
The dorsomedial striatum (DMS) is a brain structure that has been associated with important behavioral functions such as instrumental learning, behavioral flexibility and food consumption. However the role of the DMS in Pavlovian appetitive conditioning and consumption of high-fat foods has yet to be established. Here, we performed excitotoxic lesions of the DMS along with sham-lesioned controls in rats and examined their behavior during an appetitive Pavlovian discriminative conditioning paradigm and subsequent reversal of this learning, followed by high fat diet (HFD) consumption tests. In the training sessions, rats were presented with a tone and white noise separately as conditioned stimuli (CS), where rats received one cue paired with food (CS+) and the other cue presented alone (CS-). The cues were counterbalanced within each group. In the reversal phase of the experiment, the cues were switched, such that the CS- was now paired with food (now rCS+), and vice versa. Finally, rats received consumption testing, where the consumption of chow and a high fat diet (HFD) during a 6-hour period was measured, as well as the subsequent overnight consumption of chow. The results showed that rats with lesions of the DMS demonstrated attenuated responding to the CS+ early in training. Despite the effect on CS+ training, there were no significant differences between groups on CS- responding, or on either cue during the reversal phase of the experiment. Finally, lesioned animals consumed more chow overall than sham animals during the consumption tests, while no differences in HFD consumption were observed. These results suggest that the DMS is involved in learning associations between cues and reward in appetitive Pavlovian conditioning, and in the regulation of chow consumption. Further work is needed to determine the mechanisms, including the neural circuitry, through which the DMS drives these behaviors.
The Effects of Emotional Faces on Children’s Numerical and Counting Abilities
Advisors: Sara Cordes and Karina Hamamouche
Significant research exists on the ability of emotion to guide and enhance visual attention (Phelps, Ling, & Carrasco, 2006). However, little information has been obtained about the impacts of emotion on counting and approximate number skills, two numerical processes that rely heavily on attentional focus. Further, due to the fact that children lack a complete understanding of cardinal number meaning in early development, counting and numerical concepts are two areas of attentional focus that are highly susceptible to the impacts of emotional stimuli. Thus, the current study investigates the effects of emotional facial stimuli on children’s numerical and counting abilities. Two- to five-year-old children were asked to complete tasks that assessed approximate number skills and counting accuracy in the presence of happy and neutral faces, and were subsequently divided into subset-knower and cardinal-principle-knower groups based on their performance in the Give-N task. The results of this study confirmed our hypothesis that positive emotional stimuli would lead to increased attention, and thus more accurate counting, in the subset-knower group. However, this effect of was not found in the CP-knower group, likely because these children already possessed a proficient understanding of cardinal number. The fact that the subset-knower group performed better on the happy face trials over the neutral face trials in the counting task suggests that children who do not yet possess a proficient cardinal understanding of number are more likely to be impacted by emotional stimuli in numerical tasks.
An Evaluation of Baseline Data Concerning Intensive Orchestral Training and Predictors of Academic Achievement
Advisors: Ellen Winner and Sara Cordes
Many studies point to promising correlations between musical training and child development outcomes. However, no studies have explored whether a causal link exists. More specific and greater understanding of the effects of music education could help guide the arts education goals and curricula of children around the world. Ellen Winner’s Arts and Mind Lab and Sara Cordes’ Infant and Child Cognition Lab at Boston College have joined together to perform the first randomized controlled study investigating this relationship in a three-year longitudinal study with two cohorts beginning in kindergarten. Specifically, cognitive development is evaluated via measures of executive function, while affective development is measured via self-perception of cognitive competence and peer acceptance. The overall study will delve even more into the data, addressing whether orchestral ensemble music children make greater gains than control children on executive functioning, self-perception, and school liking. As part of this study, the first year’s data for cohort 1 was evaluated for baseline differences. No overall baseline differences were found in measures of executive function or self-perception of cognitive competence and peer acceptance. Some within-site differences were found. For example, at one school site the treatment group scored lower on self-perception of peer acceptance than the control and on one task of executive functioning, but performed in a different EF task. Overall, however, baseline data for cohort 1 confirmed a lack of pre-existing differences between the groups that would compromise the validity of future data analysis and conclusions.
Of Mice and Rats: Conservation as well as Unique Patterns of Sex Differences in Oxytocin Receptors in the Brain
Jingting C. Yuan
Advisors: Alexa H. Veenema and Nicholas B. Worley
The neuropeptide oxytocin (OT) regulates a wide range of social behaviors such as social recognition, social bonding, and maternal behavior by acting on oxytocin receptors (OTR) located in specific areas of the brain. The OT system often regulates social behavior in sex-specific ways, and this could be mediated by sex differences in in the OT system. Furthermore, the sex differences in the brain OT system may also underlie the sex bias in diseases such as autism and schizophrenia, where males show higher prevalence. Our lab has recently demonstrated that sex differences in OTR binding densities in multiple forebrain regions of rats correlate with social interest in sex-specific manner. However, it is important to recognize that social behavior may be species-specific, and studies done on rats may not always generalize to other species. In addition to rats, mice are an important model organism in particular because of the ability to manipulate its genome directly. By adding or removing a gene, we can better understand its function in the body such as its possible role in the development of the sexual dimorphic OT system and implications in behavioral differences in a sex-specific way. Therefore, the aim of the current study was (1) to determine sex differences in OTR binding densities in the mouse brain and (2) to compare these sex differences with those found previously in rats. We hypothesized that because rats and mice are closely related species, they would demonstrate sex differences in OTR binding densities in the same brain regions and in the same direction. We found that male mice show higher OTR binding density than female mice in the posterior bed nucleus of the stria terminalis, lateral septum, and medial amygdala. This is consistent with sex differences in the same brain regions and in the same direction as those found in rats. Furthermore, there was no sex difference in OTR binding density in the central amygdala in mice or in rats. Interestingly, we found that female mice exhibit higher OTR binding density than males in the ventromedial hypothalamus. This is in contrast to rats, where males exhibit higher OTR binding density than females in this region. Overall, these results demonstrate the conservation as well as the species-specific direction of sex differences in OTR binding density between rats and mice. These findings provide a useful reference for future experiments involved in understanding the function of the OT system in both sexes and across species.